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Pflügers Archiv

, Volume 403, Issue 2, pp 222–224 | Cite as

The effect of high K+ depolarization and verapamil on45Ca2+ fluxes in the canine myocardium

  • N. J. Lodge
  • A. L. Bassett
  • H. Gelband
Heart, Circulation, Respiration and Blood; Environmental and Exercise Physiology Short Communications

Abstract

The effects of high K+ depolarization and verapamil on Ca2+ uptake and the total intracellular Ca2+ content of canine ventricular muscle strips (∼0.5 mm thick) were investigated. High K+ (96 mM) increased Ca2+ uptake above control and maintained this enhanced uptake throughout a 90 second measuring period. Verapamil (5×10−6M) significantly (p<0.05) inhibited this high K+ stimulated uptake. However, verapamil (5×10−6M) also had a direct effect on Ca2+ fluxes, causing a significant increase in both Ca2+ uptake (p<0.001) and total intracellular Ca2+ content (p<0.001) in the resting tissue. Therefore, verapamil's apparent inhibition of high K+ stimulated Ca2+ uptake may have resulted from some mechanism other than Ca2+ channel blockade.

Key words

Canine ventricular muscle Calcium Potassium depolarization Verapamil 

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Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • N. J. Lodge
    • 1
  • A. L. Bassett
    • 1
  • H. Gelband
    • 1
  1. 1.Department of Pediatrics, Division of Pediatric CardiologyUniversity of Miami, School of Medicine (D-820)MiamiUSA

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